Pivotable seat, especially for a flight attendant

ABSTRACT

In a pivotable seat especially for a flight attendant in an aircraft, the backrest and the seat part are constructed to be pivotable together about an approximately vertical axis when the seat part is pivoted about an approximately horizontal axis into an upright position. The seat is secured to a carrying structure of the aircraft. The seat plate (25) and the backrest carrier plate (27) are milled parts. A spring is activated by tilting the seat part (2) into an upright position, whereby the seat 1 is biased into a recess (15) for storage. For pivoting the seat out of the use position into the recess (15) during non-use, only the locking of the seat part must be released and the seat part tilts itself into the vertical position, whereby the mentioned spring is activated for pivoting the seat into the recess (15) and locking it automatically in the recess.

FIELD OF THE INVENTION

The invention relates to a foldable seat especially for use by a flightattendant in an aircraft.

BACKGROUND INFORMATION

Prior seats of this type comprise an inner frame for taking up any loadswhich are active on the seat and an outer covering for appropriatelydefining the shape of the seat. In this context it is known to producethe carrying frame, for example as a welded construction of light metaltubes or profile sections, or as a cast part of a corresponding lightmetal alloy.

For the welded construction a relatively large number of separate partsmust be produced, prepared, and connected with each other in severalwelding operations, whereby this manner of production entails a highlabor cost.

In the case where the carrying parts of the seat are produced as castparts, the possibility exists to construct the respective part as asingle component with all the details. However, it must also beconsidered that, for cast parts for reasons of material strength,material additions are necessary which have a disadvantageous effectwith regard to the weight. Besides, cast parts still require a millingoperation. Furthermore, on the one hand the use of the die castingprocess is only economically worthwhile for relatively large numbers ofparts due to the high costs of a corresponding mold, and on the otherhand, the use, for example, of a high quality casting process entailshigh labor costs even for small numbers of parts.

Because of the permit requirements for seats in aircrafts, theproduction thereof requires exhaustive production controls includingX-ray examinations of welded constructions and of cast parts.

It has been observed that prior seats of this type have the habit that,after the seat has been pivoted into its recess, the seat could tiltitself out of its recesses again, if the pivoting into the recess is notcarried out according to the proper method, that is to say, until securelocking is achieved Thus, in an emergency situation the seat might blockan important escape route or hinder rescue measures

OBJECT OF THE INVENTION

Accordingly, it is the object of the invention to construct a seat ofthe above general type in such a manner, that it may be produced atlower costs and with a lower weight while posing a lower accident riskwhile still meeting the above mentioned permit requirements.

SUMMARY OF THE INVENTION

According to the invention there is provided a pivotable seat,especially for a flight attendant in an aircraft, wherein a backrestwith a seat part is constructed for pivoting about an approximatelyvertical axis and the seat surface is constructed for pivoting about anapproximately horizontal axis secured to a carrying structure of theaircraft, characterized in that carrying parts of the seat, such as theseat plate and the back plate, are constructed as one-piece milled partsand/or a spring is provided which is activated by tilting up the seatpart and pivots the seat into a recess.

The suggested seat may be produced at a lower cost and has a lowerweight as compared to prior seats. In order to pivot the seat out of theuse position into a recess for storage during non-use, only the lockingof the seat part must be released, whereby, the seat part tilts itselfinto the vertical position thereby activating a spring which pivots theseat into the recess. The locking in the pivoted-in position is achievedautomatically.

In addition to the advantage of effectively storing the seat even underunfavorable space conditions, known as compared to from pivotable seats,the suggested seat has the further advantage that malfunctions cannotarise as they tend to do in seats which are manually pivotable.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention shown in the drawings will now be described in detail byway of example, with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of the present seat ready for use;

FIG. 2 is the seat of FIG. 1 pivoted into its recess, whereby the backof the seat is visible;

FIG. 3 is a view in the direction of arrow A shown in FIG. 1, wherebythe backrest, headrest, and hinging structure are visible;

FIG. 4 is a view in the direction arrow B shown in FIG. 1;

FIG. 5 shows a section 5--5 according to FIG. 3;

FIG. 6 shows a section 6--6 according to FIG. 3;

FIG. 7 shows a bearing support of a locking lever for holding the seatin its recess;

FIG. 8 shows a section 8--8 according to FIG. 4;

FIG. 9 illustrates an attachment of an automatic belt retraction rollerto a backrest carrier plate;

FIG. 10 is a locking mechanism for holding the seat in its recess;

FIG. 11 is the mounting of a stop loop also shown in FIG. 2;

FIG. 12 is a view in the direction of the arrow 12 onto the bearingsupport of FIG. 7;

FIG. 13 shows the carrying part or frame for the backrest;

FIG. 14 shows a section 14--14 according to FIG. 13;

FIG. 15 shows the carrying part or frame for the seat surface; and

FIG. 16 is a view in the direction of arrow 16 in FIG. 15.

DETAILED DESCRIPTION OF PREFERRED EXAMPLE EMBODIMENTS AND OF THE BESTMODE OF THE INVENTION

FIG. 1 shows a seat 1 comprising a seat part 2, a backrest 3, a headsupport 4, and a belt system including two shoulder belts 5, a two-piecelap belt 6 with a central lock 7 which also receives the ends of theshoulder belts 5. Two side struts of which only the visible left sidestrut 10 is shown, are located one on each side of the backrest 3. Theseat part 2 is supported to be tiltable about an approximatelyhorizontal axis 9 within the side struts. The backrest 3 with the seatpart 2 is in turn constructed to be tiltable about an approximatelyvertical axis 8. Two hinge connections or joints are provided for thispurpose, whereby the upper one is visible in the Figure. The upper hingeconnection or joint comprises a fitting 11 connected to the aircraftstructure and a seat side fitting 12. In its position ready for use asshown in FIG. 1, the seat 1 is connected at three points to the aircraftstructure, namely at the above described hinge connections 8 and 9 andat a bearing point which is located under the right corner of the seatpart 2 as shown in the Figure. Here, the seat part 2 is releasablyconnected with the aircraft structure 1' by means of a locking mechanism13 operable by a lever 14. When the seat 1 is not needed, it may bepivoted into a recess 15 by rotation about the axis 8 after the seatpart 2 has been tilted up. In order to achieve this, first the lockingmechanism 13 is released by means of the lever 14 so that the seat part2 is tilted into the vertical storage position by means of a springforce. Thereupon, the entire seat 1 is pivoted into the recess 15. Whenthe seat 1 is fully pivoted into the recess 15, a further lock catchesautomatically, whereby the seat 1 is fixed in its storage position.

FIG. 2 shows the seat 1 in a pivoted-in position, whereby the backsideof the backrest 3 with its covering 33 and the recess 15 in the aircraftstructure are visible. FIG. 2 also shows the hinging axis 8 with theupper hinge joint comprising the fittings 11 and 12 while the lowerjoint comprises the fittings 16 and 17. A stop loop 18 hinged at its oneend to a point 20 to the backrest 3 and comprising at its other end aslot hole of the length x. A bolt 21 is arranged on the side of theaircraft structure 1' and reaches into the slot hole for guiding thestop loop 18. The pivoting angle of the seat 1 is defined by the lengthx of the slot hole. A tapered pin 22 is furthermore arranged in theaircraft structure 1' for fixing the seat 1 in both positions. Forfixing the seat 1 in the pivoted-in or stored position, the tapered pin22 cooperates with a locking lever 22a. For unlocking out of thisposition, the locking lever 22a is pressed upwardly, whereby the lockingis released and the seat 1 may be pivoted out of the recess 15.

FIG. 3 shows the view in the direction of the arrow A shown in FIG. 1without the surrounding aircraft structure 1' with the backrest 3, thetilted-out seat part 2, the head support 4, the side struts 10 and 10',the two shoulder belts 5, and the hinge fittings 12 and 17. The dashedlines the course of the parts of the shoulder belts 5 which are notvisible and which are each connected to an automatic belt retractingroller 23. A helical spring 74 with stop shanks 75, 76 is provided forpivoting the seat into the recess 15 of the aircraft structure 1'. Theshank 75 of the spring 74 is supported against the fitting 77 and ofwhich the shank 78 bears against the aircraft structure 1', whereby, thespring 74 is guided by the bearing or hinging bolt 78.

FIG. 4 shows a view in the direction of the arrow B in FIG. 1, therebyessentially showing a top view onto the seat part 2 with the side struts10, 10', the head support 4, and the hinge fitting 12 of the verticalhinge. An extension 24 for receiving the locking mechanism 13 with thelever 14, is integrated into the a seat carrying plate 25 of the seatpart 2.

FIG. 5 shows the section 5--5 according to FIG. 3, with the seat part 2,the backrest 3, and the head support 4, whereby individual elements ofthe above named components are visible. Thus, the seat part 2essentially comprises the seat carrying plate 25 and a seat cushion 26.The backrest 3 and the head support 4 are integrated into one structuralgroup or unit by a common backrest carrier plate 27 supporting a backcushion 28 and a head cushion 29. The cushions 26, 28, 29 are producedof a suitable foam material. The locking mechanism 13 with the lever 14is attached to the seat plate 25. The plates 25 and 27 are constructedas milled parts produced of an appropriate light metal alloy. The sidestruts 10, 10' are embodied in a similar advantageous manner. A belt pan27a is embodied as a sheet metal part and is connected by screws to thebottom edge of the backrest carrier plate 27 as well as to the sidestruts 10.

FIG. 6 shows in section the attachment of the hinge fitting 12 to thebackrest carrier plate 27 by four screws 30 of which the two upperscrews are visible. The screws 30 pass through corresponding boredthrough holes in the side strut 10' and are screwed to the backrestcarrier plate 27 and to a fitting 32, which comprise correspondinginside threads 31. FIG. 6 further shows the backrest cushion 28 and arear covering 33 also visible in FIG. 2.

FIG. 7 shows the support of the locking lever 22a, comprising a pin 34set into the side strut 10' and supported by means of a fitting 35screwed to the belt pan 27a.

FIG. 8 shows a section view of details of the support of the seat part 2about the axis 9 with a hinge pin 36 which rests in the wall 25a and arib 25b on the side of the seat plate 25 and which is pushed into anappropriate, bored hole within the side strut 10. A correspondingarrangement is provided on the opposite side of the plate 25. The momentfor biasing the seat part 2 into the upright position is applied by twohelical springs 37 of which one is shown here. One shank of the spring37 engages a rib, not shown, of the plate 25, whereas the other shank ofthe spring contacts a stop which is not visible here, but which islocated on the belt pan 27a. After the pin 36 is mounted, it is securedby a split pin inserted into a bored hole 38.

FIG. 9 shows in section a detail of the backrest carrier plate 27supporting the cushion 28 with one of the two automatic belt retractingrollers 23 for a shoulder belt 5. The automatic retractor 23 is attachedto the plate 27 by means of screws 39. The pertinent area of the plate27 is strengthened for taking up any possibly arising belt forces.

FIG. 10 shows the locking mechanism 13 for locking seat part 2 in itshorizontal use position. The mechanism 13 cooperates with the taperedpin 22 and essentially comprises the mentioned locking lever 14, ahousing 40, and a helical spring 41 with shanks for causing a leftrotating counterclockwise moment as seen in the FIG. 10 on the lever 14about the rotation point 42. The lock 13 is shown together with thetapered pin 22. The pin 22 comprises a side slot of the thickness of thelever 14 at the location of contact with the lever 14 in such a mannerthat the lever 14 can reach approximately half way into the pin 22. Inorder to fix the seat 1 in the horizontal use position, the seat part 2must simply be tilted downwardly, whereby, the lever 14 abuts againstthe tapered surface of the tapered pin 22 and glides along thereon untilthe lever 14 catches in said slot. Now, the seat part 2 is rigidlyconnected with the aircraft structures 1' and can only be released againin that the lever 14 is manually pivoted out of the slot against thebias of the spring 41.

FIG. 11 shows the attachment of above mentioned stop loop 18 to the sidestrut 10'. For this purpose, a bolt 43 with a washer 44 is providedsecured by a split pin 45.

FIG. 12 shows the locking lever 22a in a side view with its rotation orjournalling point 46. The lever 22a protrudes through an opening locatedin a recess. A leg helical spring 47 applies a right rotating orclockwise moment as seen in FIG. 12 to the lever 22a which comprises abow-shaped section 49, whereby the lever 22a rests against a contactstop 48. At its lowest point, the lever 22a comprises a tapered boredhole 50. During pivoting of the seat 1 into the storage position, thelever 22a approaches the tapered pin 22 and contacts it with itsbow-shaped section 49, whereby the lever 22a deflects upwardly until thelocation of the tapered bored hole 50 reaches the pin 22. In thisposition the lever 22a again jumps downwardly, whereby the pin 22 entersthe tapered bored hole 50. Thus, the seat 1 is fixed in its pivoted-instored position.

FIG. 13 shows the backrest carrying plate 27 embodied as a milled partas viewed in the direction of the arrow XIII in FIG. 5. The productionof high strength, light structural components by means of milling istypical in the aircraft industry, whereby the advantage is put to usethat the pertinent parts can be optimally adapted to the loads at hand.Typical structural components of this type in principle always comprisean open or closed milled skin which is stiffened in an appropriatemanner by ribs. In this context such a milled construction is a furtherdevelopment of a sheet metal construction, whereby the separate elementsof the structural component, such as the skin and the ribs, aremanufactured of sheet metal and connected to one another by riveting.However, the milled construction is advantageous relative to the sheetmetal construction insofar as riveting overlaps and the point forcetransmission in the regions of the separate rivets are therebyeliminated. Since the ribs are integrated in a one-piece manner with theskin to form one part, such milled parts are also named integralstructural components, integral parts, or integral plates. A finishedmilled part of this type only contains approximately 10% of theoriginally present material and was previously regarded as quiteexpensive in comparison to parts produced in a different manner due tothe necessary machining expenditure. Only since a larger number ofequivalent milled parts may be simultaneously produced in a numericallycontrolled milling operation, is milling competitive with casting or diecasting with regard to production costs.

The backrest carrier plate 27 comprises a milled skin 51 with stiffeningribs 52 in the upper portion and diagonally crossed ribs 52' in thelower region 63 for the backrest. The ribs 52' have top flanges 53according to the invention, whereby, the ribs 52' protruding from theskin 51 have a T-shaped cross-section. Another top flange 57 isintegrated in a one-sided manner with the respective rib so that thecross-section of this rib comprises an inverted L-shape. The integratedhead part of the seat will be formed by the upper region 64 of theintegral backrest carrier plate 27. Here, guide elements 58 and a beltreturn guide 59 are integrated. The guide elements 58 are used with thearrangement of automatic belt retracting rollers 23, whereas the returnguide 59 is provided for rigidly mounted shoulder belts of which thesecured ends are held by an integrated bail 65. Thus, the possibilitiesof a milled construction are used to integrate elements into thebackrest carrier plate 27 in a one-piece manner which previously wereproduced and mounted as separate structural components. Threaded insertbores 56 are provided for securing the automatic belt retracting rollersand for securing carrying elements. Due to the bores 60, the backrestcarrier plate 27 may be attached by screws to the side struts 10, 10'.The threaded bores 61 and the through-hole bores 62 serve for securingthe belt pan. Cut-outs 54 and bores 55 are provided for reducing theweight. As shown in FIG. 5, the backrest carrier plate 27 is installedin such a manner that the milled skin 51 faces the cushions. The flanges53 and 57 and the ribs 52 and 52' form the rear limit of the carrierplate 27. An essential characteristic of this plate is seen in thatbesides the stiffening ribs it comprises all further necessary elementsor provisions for mounting the plate itself as well as for mounting allfurther structural components connected with the plate.

FIG. 14 shows a section through a rib 52' according to FIG. 13. Here,the T-shaped cross-section of the rib 52' is seen which is formed by theintegration of the flage 53. The milled part forms a quasi-double-Tcarrying element with the milled skin 51 as the lower flange, the rib52' as a web, and the upper flange 53.

FIG. 15 shows the milled seat plate 25. Here also the ribs 52' areprovided with flanges 53 and thereby have a T-shaped cross-section. Themilled skin 51, as well as the corner node points, comprise bores 55 forreducing the weight. The seat plate 25 is bounded by the sides 66, 67,68, and 71 and is provided with axial bores 70, whereby the skin 69covers the axial spring 37 shown in FIG. 8. The threaded bores 72, andthe pin bores 73, on the extension 24, are provided for securing thelocking mechanism 13, whereby the extension 24 is integrated with theplate 25 in the above described manner.

FIG. 16 shows the view in the direction of the arrow 16 in FIG. 15.Here, the thickness d of the plate 25 and the position of the bores 70and the skin 69 are shown.

As a result of the embodiment, especially of the seat plate 25, and ofthe backrest carrier plate 27 as integral structural milled components,the possibilities of the milling process are put to good use here, toincorporate all the elements necessary for reasons of strength, such asthe skin, ribs, edge carriers, and all elements necessary for mounting,such as the threaded bores, through-hole bores, extensions, etc. in aone-piece manner, into the respective structural parts.

Although the invention has been described with reference to specificexample embodiments, it will be appreciated, that it is intended tocover all modifications and equivalents within the scope of the appendedclaims.

We claim:
 1. A tiltable seat structure, especially for a flightattendant in an aircraft, comprising a seat section with a one-pieceseat plate and a backrest section with a one-piece backrest carrierplate, first hinging means for journalling said seat section to saidbackrest section, first spring means urging said seat section up againstsaid backrest section, second hinging means for journalling saidbackrest section and said seat section to a structural member of saidaircraft, second spring means for automatically biasing said backrestsection with said seat section into a storage position in a recess insaid structural member when said seat section is in an upright position,first locking means (13, 14; 41) secured to said seat section forlocking said seat section in a use-position, second locking means (22a)secured to said backrest section for locking said backrest section andsaid seat section in said storage position, a tapered pin (22) securedin a fixed location to said aircraft structure in a position forcooperating with said first locking means to hold said seat section inits use position and for further cooperating with said second lockingmeans (22a) to hold said backrest section and said seat section in saidstored position in said recess, whereby said tapered pin (22) holds saidseat in said use-position and in said storage position.
 2. The seatstructure of claim 1, further comprising single-piece side struts (10,10') secured to said one-piece backrest carrier plate, said firsthinging means securing said seat section to said single-piece sidestruts.
 3. The seat structure of claim 1, wherein said one-piecebackrest carrier plate comprises integral stiffening ribs and means formounting as integral components of said one-piece backrest carrierplate.
 4. The seat structure of claim 3, wherein said integral ribs (52,52') comprise top flanges (53) for forming a T-cross-section.
 5. Theseat structure of claim 3, wherein said integral ribs (52, 52') compriseone-sided flanges (57) for forming an L-cross-section.